The present invention relates to novel carbacyclin esters, a process for their preparation, and their use as medicinal agents.
(5E)- and (5Z)-6a-carbaprostaglandin I.sub.2 analogs are disclosed in German Unexamined Laid-Open Application DOS Nos. 2,845,770; 2,900,352; 2,902,442; 2,904,655; 2,909,088; 3,209,702; 3,204,443; 3,048,906; and 2,912,409, all of whose disclosures are incorporated by reference herein.
The nomenclature of the compounds of this invention is based on a proposal by Morton and Brokaw (J. Org. Chem. 44 : 2880 [1979]). The synthesis of these compounds yields in all cases two double-bond isomers characterized by the symbols (5E) or (5Z). The two isomers of this prototype are clarified by the following structural formule: ##STR4##
It is known from the very voluminous state of the art of prostacyclins and their analogs that this class of compounds is suited for the treatment of mammals, including man, because of its biological and pharmacological properties. The use of these compounds as medicinal agents, however, frequently meets with difficulties since their period of effectiveness is too short for therapeutic purposes. All structural modifications in these compounds are aimed at increasing the duration of their effectiveness as well as their selectivity of efficacy.